Spring unit



Feb. 24, 1970 N. L. RIDDLE ETAL SPRING UNIT Filed Aug. 30, 1967 E INVENTORS ALBIN J. NIEWULIS NEVILLE L. RIDDLE ATTORNEYS United States Patent Oiiice 3,497,200 Patented Feb. 24, 1970 3,497,200 SPRING UNIT Neville L. Riddle, Lexington, and Albin J. Niewulis, Georgetown, Ky., assignors to Hoover Ball and Bearing Company, Saline, Mich., a corporation of Michigan Filed Aug. 30, 1967, Ser. No. 664,553 Int. Cl. F16f 1/14, 3/02 US. Cl. 267110 Claims ABSTRACT OF THE DISCLOSURE A seating structure having spaced frame rails and load supporting spring units attached to and extending between said rails. Each spring unit is a zigzag wire construction having spaced transverse torsion bars connected by spacer bars, one end of the unit being attached to one face of one frame rail so that the endmost torsion bar is in a plane parallel to and in engagement with said one face, and the other end of the unit is similarly attached to the other rail. Each of the endmost torsion bars terminates in an end or stabilizing bar extending inwardly in an angular relation thereto in the plane of its torsion bar. The spring units are secured to the frame rails by staples located on opposite ends of the torsion bars.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to improvements in spring units for seating structures of the type shown in US. Patent No. 3,282,583.

In seating structures of the type shown in the aforesaid patent, the spring unit is attached at its opposite ends to upper and lower wood frame rails by means of prongs which extend angularly from the terminus of each endmost torsion bar into a corresponding opening in the mounting face of each frame rail. This arrangement provides a very satisfactory seating structure which eliminated objectionable noises, and these desirable results are realized while providing optimum load resistance characteristics in relation to the size of wire used to form the units.

The present invention provides the same desirable results but enables the seating structure to be constructed without the necessity of forming the holes or openings in the frame rails for receiving prongs, thus simplifying the fabrication of parts and the subsequent assembling operation.

According to one form of the present invention, a spring unit is formed having transverse torsion bars at opposite ends, each torsion bar terminating in a stabilizing bar extending inwardly in angular relation to its associated torsion bar. In assembling the seating structure the torsion bars are stapled to the frame rails with each torsion bar and its stabilizing bar in a common plane parallel to the face of the associated rail to which such torsion bar is secured.

It is an object of the present invention to provide an improved load supporting spring unit for a seating structure which is constructed and arranged to provide optimum load carrying capacity, quiet operation and ease of fabrication and assembly.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawing forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a vertical sectional view of a seating structure having the improved spring unit of this invention incorporated therein, and illustrating the spring unit in an unloaded position;-

FIGURE 2 is a vertical sectional view similar to FIG. 1, showing the spring unit in a loaded position;

FIGURE 3 is an enlarged fragmentary front elevational view, showing one arrangement for securing the spring unit to a frame rail;

FIGURE 4 is an enlarged fragmentary end elevation of the arrangement shown in FIG. 3;

FIGURE 5 is a vertical sectional view of a modified form of the spring unit of this invention, and

FIGURE 6 is a vertical sectional view of still another modified form of the spring unit of this invention.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION With reference to the drawings, the spring unit of this invention, indicated generally at 10, is incorporated in an upholstered furniture seat back assembly 12 which includes an upper wood frame rail 14, a lower wood frame rail 16, and upholstery padding material 18 applied to the rails 14 and 16 and the unit 10. The illustrated embodiment of the invention consists of an elongated main or body spring 20 and a support spring 22, which is secured to and positioned on the rear side of the body spring 20. Both springs 20 and 22 have a resilient resistance to lateral bending characteristic and are described enerally as zigzag springs in that they have wire having transverse torsion bars, adjacent ones of which are connected to spacer bars.

The support spring 22 has a portion 28 which is formed by a pair of diverging legs 30 and 32. The body spring 20 can be conveniently described as having a lower portion 34 and an upper portion 36, and an extension 38 of the leg 30 is secured by clips 40 to the upper end portion 36, as shown in FIGS. 1 and 2. The upper end of the leg 32 is formed with an endmost torsion bar which has at its terminus an end or stabilizing bar 44 which extends inwardly in angular relation to the torsion bar. In the illustrated embodiment of the invention the stabilizing bar 44 is disposed at right angles to the torsion bar 42.

As shown in FIGS. 1 and 4, the stabilizing bar 44 is formed so that it is in the plane of the torsion bar 42 parallel to the face 46 of the frame rail 14 when the spring unit 10 is in its assembled position. The torsion bar 42 is secured to the frame rail 14 by means of the staples 48 and 50 which straddle opposite ends of the torsion bar 42. The endmost torsion bar 52 at the other end of the spring unit 10 is similarly secured to the lower frame rail 16, and, as can be seen best in FIG. 1, the torsion bar 52 also terminates in an end or stabilizing bar 54 which extends inwardly in angular relation to the torsion bar 52. The torsion bar 52 and the stabilizing bar 54 are in a common plane which is parallel to the face 56 of the lower frame rail 16 to which the torsion bar 52 is secured by staples, not shown.

When assembling the various components forming the seating structure 12, the spring unit 10 can be stapled directly to the frame rails 14 and 16 without the necessity of performing any manufacturing operations, such as forming holes in the frame rails, thus simplifying the fabrication of the frame rails 14 and 16 and also eliminating the necessity of inserting prongs into holes formed in the frame rails. Thus, the fabricating and assembling of components are simplified.

In use, the described embodiment of the invention will function without producmg undesirable noises resulting from squirming of the torsion bars 42 and 52 with respect to their frame rails 14 and 16. This desirable feature of the present invention is realized because of the cooperation between stabilizing bars 44 and 54 and their associated torsion bars 42 and 52 and the arrangement for securing the torsion bars 42 and S2 in place. By virtue of the fact that the stabilizing bars 44 and 54 are each in a common plane with their torsion bars 42 and 52 and each such plane is parallel to the face of the frame rail on which the stabilizing bars are secured, squirming of the torsion bars on the frame rail faces during loading and unloading of the spring unit 10 is prevented. It will be recognized by those skilled in the art when a load L is applied to the seating structure 12, the components of force acting at the end-most torsion bars will urge the stabilizing bars perpendicularly against the faces of the rail frames on which the torsion bars are secured. Thus, when a load is applied to the spring unit 10, the stabilizing bars tend to increase the holding action against the surface of the associated face of the rail frame and this holding action together with the holding action of the staples prevents squirming of the endmost torsion bars on the faces of the associated frame rails.

FIG. 5 illustrates a modified form of the spring unit a which has its endmost torsion bars 42a and 52a stapled to frame rails 14a and 16a in substantially the same manner as was described with respect to the embodiment of the invention illustrated in FIGS. 1-4. FIG. 6 illustrates still another embodiment of the spring unit 10b which also has its endmost torsion bars 42b and 52b stapled to frame rails 14b and 16b in the same manner as was described with respect to the embodiment of FIG. 1. In the embodiment of the invention shown in FIGS. 5 and 6, stabilizing bars 44a and 44b are used with their associated torsion bars to provide the same holding action that is provided in the embodiment of FIG. 1. In a like manner, torsion bars 52a and 52b terminate in stabilizing bars, not shown, which functon in the same manner as the stabilizing bar 54 of the embodiment illustrated in FIG. 1.

From the foregoing description it will be understood that the improved construction and arrangement for mounting the spring units 10, 10a and 10b on frame rails is not limited to a specific form of spring unit and that the invention is not necessarily limited to a spring unit having zigzag wires, but the invention applies to any form of spring unit which utilizes a transverse torsion bar at one or both ends of the spring unit. It is also to be understood that while the units 10, 10a and 10b have been illustrated and described with particular reference to their inclusion in a vertical seat back assembly, each unit is also usable in a generally horizontal position as part of a bench portion of a seating structure. Consequently, the terms upper, lower, etc. are intended herein as terms of reference and not as terms of limitation.

Having thus described our invention, we claim:

1. In a seating structure which includes spaced frame rails, a load supporting spring unit attached to and extending between said rails, siad spring unit being a wire construction having a transverse torsion bar at one end disposed so that on loading of said spring unit said torsion bar is subjected to torsional stress, said one end of said unit being attached to one face of a frame rail so that the torsion bar is in a plane parallel to and in engagement with said one face, said torsion bar terminating in an end bar extending inwardly in an angular relation thereto in said plane, and means attaching said torsion bar to said frame rail.

2. In a seating structure according to claim 1, wherein said means comprise staples straddling opposite ends of the torsion bar and driven into said frame rail.

3. In a seating structure according to claim 1, wherein the other end of said unit has a transverse torsion bar which is attached to one face of a second frame rail so that the torsion bar at said other end in a plane parallel to and in engagement with said one face of the second frame, the last-named torsion bar terminating in an end bar extending inwardly in an angular relation thereto in said plane, and means are provided attaching the lastnamed torsion bar to the second frame.

4. In a seating structure according to claim 1 wherein said spring unit includes a leg which extends toward said frame rail face at an acute angle relative to said face, said leg terminating in said torsion bar, said torsion bar and said end bar being disposed on said face so that said torsion bar is effective to yieldably resist movement of said leg in a direction to reduce said angle.

5. A spring unit for a seating structure, said spring unit including a leg which extends in one direction and terminates directly at one end in a torsion bar disposed in a plane which is at an acute angle relative to said direction, and a stabilizing bar on said torsion bar and located in said plane so that when said stabilizing bar is maintained in said plane and said leg is moved to reduce said angle said torsion bar is subjected to torsional stress.

References Cited UNITED STATES PATENTS 2,124,655 7/1938 Freund 267-' 3,282,583 11/1966 Slominski 267107 JAMES B. MARBERT, Primary Examiner 

